Effect of smoking on coronavirus disease susceptibility: A case-control study

Tobacco use has changed since the onset of the coronavirus disease (COVID-19) pandemic. The effect of smoking on COVID-19 susceptibility has not yet been determined. In this study, we aimed to assess the association between smoking and COVID-19 susceptibility.

This retrospective case-control study was conducted at the quarantine center of Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia, between April and June 2020. A total of 142 adults participated in the study, 73 of whom tested positive for COVID-19 and were matched for both sex and age with participants in the control group. Telephone interviews were conducted to assess the risk factors associated with that exposure.

Different variables are investigated for their impact on COVID-19 infection susceptibility. The current study's findings indicated that smokers comprised only 27.5% (n=39) of the participants. There was no association between the COVID-19 swab results and smoking status (χ²=1.857; p=0.395). Furthermore, there was no significant association between any of the smoking parameters and susceptibility to COVID-19, except for the smoking period (t= -2.105, p=0.041). The odds of having a positive swab result among cigarette smokers were lower than those among pipe, waterpipe, and electronic cigarette smokers (OR=0.600; p=0.394). An association was also observed between COVID-19-positive swab results and contact with an individual with COVID-19 or respiratory disease (χ²=79.270 and χ²=18.929, respectively, p≤0.001).

This study revealed no association between smoking status and COVID-19 swab test results. Further research with a bigger sample size is suggested to confirm the relationship between smoking and COVID-19 susceptibility.